1. Field
The invention relates to an overmolded electronic circuit board, and in particular, an engine controller wherein the overmold material encapsulates the circuit board providing protection for the electronics on the circuit board and providing the seals between the circuit board and mating components.
2. Background Art
Electronic modules, such as printed circuit boards used as engine controllers, cannot be used in harsh environments without protecting the modules. Circuitry and electronic componentry attached to the circuit boards must be protected from water and contaminants which can short the circuitry and cause issues with the proper function of the electronic componentry. As well, circuit boards must be protected from the high temperatures radiating from engines which can also cause damage to the circuit boards. For these reasons, engine controllers are typically placed in a less harsh environment away from the engine with wiring running from the engine controller to the other components needed to run and control the engine.
Some techniques have been developed to seal engine controller circuit boards by encapsulating the circuit board and electronic componentry on the circuit board in a rigid resin material. The rigid material requires additional seals, or additional complex precautions, to allow areas of the board to extend past the resin. O-rings and other seals are used in order to ensure that the circuit board is protected when connecting wiring to the controller. The rigid resin material also causes issues as the resin material insulates and the circuitry and electronic componentry attached to the board can be damaged by overheating during use.
Sensors used to measure engine parameters must be placed in close proximity to the engine components in order to measure the parameter. Due to this, sensors are typically mounted on, or within, engine components with wiring sending the data measured to the engine controller. Excessive wiring adds expense, potential snag/cut failures, and creates a less desirable appearance of the entire engine system.
Examples of engine controllers using a pressure sensor to control the engine operating parameters may be found in U.S. Pat. Nos. 6,804,997 B1 and 6,955,081 B2 to Schwulst, and 7,225,793 B2 to Schwulst et al., all of which are hereby incorporated by reference in their entirety.
The following references were considered in conjunction with preparing this application: U.S. Pat. No. 7,514,784 B2 to Mayuzumi et al., U.S. Pat. Nos. 7,739,791 B2, 7,553,680 B2, and 6,779,260 B1 to Brandenburg et al., U.S. P.G. Pub. No. 2010/0117308 A1 to Dell'Eva et al., K.R. Pub. No. 10-2007-0063858 to Ha et al., U.S. Pat. No. 5,257,172 to Erickson and G.B. Pub. No. 507,440 to Long.